🚀 go-pugleaf

On 10 Sep 2005 21:07:52 -0700, venkateswarag@gmail.com wrote:

>Hi,
>
>Can anyone help me in the following !!!
>How to get the list of installed printers and display the list in the
>dropdown box using Tprinter class.

  ListBox1.Items.Text := Printer.Printers.Text;

>I need to send the PCL format file to printer directly for selected
>printer from the dropdown list. 

You therefore need to bypass the printer's canvas

The simplest method I know of is to use the OpenPrinter API 
then StartDocPrinter
then possibly StartPagePrinter
then dump the contents of the file using: WritePrinter
then possibly EndPagePrinter
then EndDocPrinter
then ClosePrinter

venkateswarag@gmail.com wrote:
> 
> I need to send the PCL format file to printer directly for selected
> printer from the dropdown list.

 
If you could write that dropdown list your self. And if you can deal
with the the thing that the printers here are indentified by their
PrinterIndex number, then this snippet should do the job.


uses
  .. Printers, WinSpool;

procedure DumpAnyFileToPrinter(aFileName: string; aPrinterIndex:
Integer);
var
  BytesWritten: DWORD;
  aHandle: THandle;
  DocInfo: TDocInfo1;
  PrinterName: PChar;
  MSt: TMemoryStream;
  aErrCode: Integer;
  aFailed: Boolean;
begin
  if not FileExists(aFileName) then
    raise exception.create(Format('File not found "%S"', [aFileName]));
  try
    PrinterName := PChar(Printer.Printers[aPrinterIndex]);
  except
    ShowMessage(Format('Index [%d] outside current printer count (%d).',
      [aPrinterIndex, Printer.Printers.Count]));
    Exit;
  end;
  if not WinSpool.OpenPrinter(PrinterName, aHandle, nil) then
    raise exception.create('Printer not found');
  MSt := TMemoryStream.Create;
  try
    MSt.LoadFromFile(aFileName);
    {Name pDocName will be shown on the Print Task list.}
    DocInfo.pDocName := PChar('DUMP: ' + aFileName);
    DocInfo.pOutputFile := nil;
    DocInfo.pDatatype := 'RAW';
    if StartDocPrinter(aHandle, 1, @DocInfo) <> 0 then
    try
      if StartPagePrinter(aHandle) then
        WritePrinter(aHandle, MSt.Memory, MSt.Size, BytesWritten);
    finally
      EndPagePrinter(aHandle);
    end;
    EndDocPrinter(aHandle);
  finally
    aErrCode := GetLastError;
    WinSpool.ClosePrinter(aHandle);
    if aErrCode = 0 // 0 = Last operation Succeed.
      then MessageBox(0, PChar(Format('Success! %d bytes spooled',
        [BytesWritten])), PrinterName, mb_OK + mb_iconinformation)
    else MessageBox(0, PChar(SysErrorMessage(aErrCode)),
        'Printing Error', mb_OK + mb_iconexclamation);
    MSt.Free;
    ClosePrinter(aHandle);
  end;
end;


procedure TForm1.btnRaw2Click(Sender: TObject);
begin
  // TEST.PCL is a file created by printing through a LaserJet
  // PCL-driver, with 'Print To File' option.
  // Dump this file to the current active printer.
  DumpAnyFileToPrinter('C:\TEST.PCL', Printer.PrinterIndex);
end;

There may be even too much built in checkings, and too many hard coded
error messages for this kind of task. 

And the code is not perfect either, but it has served me through the
years, for my occasional Dump needs.

John P